Fuel injection and mixing means for internal-combustion engines



Nov. 10, 1925. 1,560,556

E. A. FORD FUEL INJECTION AND MIXING MEANS FOR INTERNAL COMBUSTIONENGINES Filed July 5, 1920 fizz/M107 3 3 WQWM M v Patented Nov. 10,1925.

UNITED. STATES PATENT. OFFICE.

EUGENE A. FORD, OF NEWTON, MASSACNUSETTS,'ASSIGNOR TO R. E. D. ENGINECOM- PANY, INC., OF NEW YORK, N. Y.

, A CORPORATION OF NEW YORK.

FUEL INJECTION AND MIXING MEANS FOR INTERNAL-COMBUSTION ENGINES.

Application filed my a,

To all whom it may concern: Be it known that I, EUGENE A. FORD, a icitizen of the United States, residing at Newton, in the county ofMiddlesex and State of Massachusettsfliave invented new and usefulImprovements in Fuel Inject on and Mixing Means for Internal-CombustionEngines, of which the following is a specification.

This invention has reference primarily to internal combustion engines ofthe high compression type, that is, the type in which air is compresseduntil its temperature is raised to the point at which it will ignitefuel, and

finely divided fuel is injected into the air so compressed. In suchengines liquld fuel 1s enerally-employed and most commonly-the fuel usedis oil of the quality commercially known as fueloil. But as other fuelsthan oil may be used, the references in the following description tofuel oil are to be taken as illustrative or typical of any liquid fuelwhich may be used in engines of this type, and not as in any sense arestriction in the scope in which protection is claimed for theinvention. 1

It is essential with engines of the type here specified that the fuel bedlvlded into the most minute particles possible and that these particlesbe thoroughly mixed with the air in the combustion chamber of the motor,in order that the fuel may be fully,

quickly, and efficiently burned, for the time period available for mixinand combustion of the fuel is extremely rief, due to the high speed atwhich such engines are commonly run and the'small proportion of thecycle during which fuel is admitted. In the well known Diesel typeengine, the fuel 011 is blown into the combustion chamber by cooled aidat a higher compression pressure than the air in the combustion chamber,and there is customarily used for that purpose albout one-tenth as muchair as already exists in the combustion chamber, and also a large excessof air (approximately 100%) more than the quantity required according tothe laws of chemical reaction for complete combustion of the fuel.

' The objects of my invention are to furnish an improved means foreffecting in ection of liquid fuelinto the combustion space of a highcompression engine, by which such a fine subdivlsion of the liquid fuel,pre- 1920. Serial No. 393,937.

liminary heating of the fuel, and intimate mixture of the fuel with thecom ressed air in the combustion chamber are e ected that only arelativel very small excess of air need be supplied to effect completecombustion; to cause combustion to commence in the central part of thecombustion chamber; and to accomplish the fuel injection and air mixingby very simple means.

The preferred form of means b which these objects are accomplished isescribed in the following specification and illustrated in the drawingsforming apart thereof; and the invention consists in said means andequivalent devices having substantially the same function and resultwithin the scope of the appended claims. In said drawings,

Figure 1 is a cross section of an engine cylinder and the fuel injectionmeans containing the form of the invention above referred to, saidsection being taken on the line 1-1 of Figure 2.

Figure 2 is a longitudinal section taken on line 22 of Figure 1.

Like reference characters designate the same. arts in both figures.

Be ore entering into a detailed description of the invention hereillustrated I would .Say that this illustration is intended to showsimply so much of an engine as is necessary to an understanding of thefundamental principles of the invention, and is not intended as arestriction to matters of detail of the scope in which I claimprotection for my invention. No attempt has been made to show structuraldetails which may be provided for convenience in a commercial form ofengine containing the invention, but all such are left to be supplied bythe designer from facts available to those acquainted with the art.Hence I have shown as integrally connected arts a cylinder 11, with aninterior partition 12, an auxiliary cylinder 13, and a connection 14between the cylinder and auxiliary cylinder, although in practice theseelements may be made of a number of parts suitably fastened to ether.

. The cylinder 11 has a hea 15 containing a port 16 controlled as toopening and closing by a valve 17 which may be operated by any effectivemechanism to be opened during the suction and exhaust'strokes and to beclosed during the compression and working strokes of the engine. Thepartition 12 cient area. to

above mentioned partly divides the combustion chamber 18 within thecylinder head. from the balance of the cylinder, but has a large opening19 in its central part of sufiiermit free flow back and forth through it0 air and products of combustion, without substantial impedance. It islocated close. to the point reached by the head end of the piston at theend of its compression and exhaust strokes. A number of passages 20 leadthrough the head from the cylinder proper and o n into the space 18through radial jet orifices 21 located approximately in a plane midwaybetween the partition 12. and the valve 17, whereby jets are driventhrough said passages in the manner presently described which convergeat and around the central point of the chamber. Said passages may beconsidered as by-pass channels which conduct air around the outer partsof the partition to the combustion space when the interior opening isobstructed, as presently explained.

22 represents the piston which reciprocates in the cylinder in the usualmanner and has a boss 23 adapted to enter and substantially fill thehole 19 at the end of the piston travel toward the cylinder head, thesurface of the cylinder surrounding such boss being at those times:nearly in contact with the partition 12.

The chamber 10, formed between the walls and head of the auxiliarycylinder 13 and the piston 26 therein, is in communication with thecombustion space 18 b a passage 24 through the connection 14, w ichextends in line with one of the jet orifices 21. This auxiliary chamberextends past the communicating passage 24 in the direction of thecompression strokes of the engine. Its head end is slightly enlarged indiameter beyond the shoulder 25. An auxiliar piston 26 o erates in thisauxiliary cy index and so c osely fits the interior thereof, except theenlarged part, that, while it may be reciprocated freely, no appreciableleakage of gas and fuel oil past it is permitted. A zone 27 of thesurface of the auxiliary piston somewhat removed from the extreme endthereof is knurled, the knurling providing a multiplicity ofintersecting helical shallow grooves; and at the lower limit of theknurled zone is an encircling deeper groove 28, from which there asses alon itudinal groove 29 in the si e next'to tie passage 24. j a i In theside of the auxiliary cylinder 15 a fuel inle'tv30 adapted to-besuppliedwith oil by a pump means which may be operated periodically to cause orpermit injection of aregulated quantity of fuel oil at given times. Ihave not shown such pump or other means, for I may use for the purposeof supplying oil in or a control valve, or any other the mannerindicated, various devices already known and used 1n. connection withhlgh compression engines. The plpe 31 coupled to the fuel inlet passa etypifies generally any means which may e provid tion be called the mainengine piston, is

coupled by a connecting rod and crank in the usual way, or by equivalentmeans, with a crank shaft, and that the auxiliary piston is driven fromthe crank shaft by mechanism which causes it to travel in general in thesame directionswith the main iston but with a variation in speedrelative y thereto in different parts of the stroke. I may use variousmechanisms for driving the auxiliary piston, such for example, as themechanism illustrated in my pending application for Letters Patent ofthe United States Serial Number 259,974 filed October 28, 1918 entitledInternal combustion motors. Such mechanism causes the auxiliary pistonto travel (in proportion to its displacement) relatively slower than themain piston during the first part of the compression stroke, andrelatively faster during the last part of such stroke and to lag behindthe main piston at the completion of the compression stroke. Preferablythe auxiliary piston reachesthe end of its compression stroke when themain piston crank has run past the dead point 15 of the cycle after fullcompression. This lagging of the auxiliary piston is provided merely toavoid generation of excessive explosion pressure when running at low.speeds, and it may be greater or less than the degree indicated, orthere may be no lag at all. Preferably also the auxiliary'pistonapproaches the head of its cylinder with no appreciable clearance inorder that substantially all of the gas and fuel oil trapped in saidcylinder may be expelled therefrom and injected into the combustionspace.

The position on the auxiliary piston and width of the grooved zone 27,the position of the encircling groove 28, and the length of the lon'tudmal groove 29 are determined with re erence to the time and durationof the fuel injection. Hence the upper limit of the knurled or groovedzone 27 crosses the shoulder 25 and and the groove 28 begins to registerwith the passage 29 at about the tion between the passage 24 and groove28 throughout the entire balance of the compression stroke of theauxiliary piston.

The mode of operation of the enginethe main piston are unimportant,since the purpose and result of the suction stroke is to fill bothcylinders with air. The auxiliary piston moves far enough to uncover theorifice of the fuel passage 30, and at some time while this orifice isso uncovered a regulated quantityof fuel oilis injected through thepassage 30. Owing to the inclination of this passage the stream of oilis thrown across the current of air coming through the passage 24,whereby a certain amount of mixing of fuel and air then takes place.

On the compression stroke the main pis ton first travels relativelyfaster than the auxiliary piston, as previously stated, whereby acertain amount of the air in the main cylinder is transferred to theauxiliary cylinder, the valve 17 being then closed. Before the auxiliarypiston begins to travel faster than the main piston, or at any ratebefore its acceleration over the main piston has become great enough tocause any a preciablereturn flow of air into the main cylinder, itcrosses and closes the entrance to the passage 24. It is possible tocause closing of this passage in this manner to take place at anyexactly determined point simply by properly determining the lengthoftheauxiliary cylinder extension beyond the passage and ofthe-corresponding'part of the auxiliary .piston, because these'dimensions can be made ofany value without causing any [modification of construction oradjustment of the auxiliary piston driving ment) traveling auxiliarypiston compresses mechanism.

' At this time thea' pressure in the two cylinders is the same, butthereafter the more rapidly (in proportionto its displacethe air in theauxiliary cylinder more and more highly above the pressure in the maincylinder.

At first during the compression in the main cylinder air passes into thecombustion space mainly through-the large opening 18,

but when the projection 23 approaches and.

enters such opening possibility of flow there through is substantiallyexcluded and the air: trapped between the projection, the flanking endwall of the iston, and the partition, is then forced to fibw through thepassages 20, and is violently impelled through the jet orifices 21toward the center of the combustion chamber. About at the time when thisaction commences, the grooved zone 27 commences to cross the shoulder 25bounding the enlarged chamber in the head part of the auxiliarycylinder, whereupon oil under pressure of the air entrapped in saidchamber is forced in many zigzag channels through the grooves of theknurling to the encircling groove 28, and thence through the passage 24.The passage of the oil through these narrow zigzag channels breaks it upinto as small particles as is practically and thehig and increasingpressure of air above the piston propels these particles with greatvelocity and compels an intimate mingling of air with them. Part of thessible to be done mechanically,

fuel is vaporized and that which remains in a thorough and intimate waywith the separated particles of liquid and vaporized oil, whereby thematter which enters the deep encircling groove '28 and streams throughthe communicating passage into the combustion chamber is an intimatemixture of fuel and air.

This stream of air and oil particles violently forced through thecommunicating passage mingles with the stream of air I flowing throughthe nearest one of the bypass channels 20, 21 and is carried with theair stream into the center of the combustion chamber. As all of. the airthen in contact with the fuel is com ressed to a temperature higher thanthe ignition temperature, the oil is ignited. Combustion in largemeasure commences at the center of the combustion space, where thestreams of air from the by-pass channels meet; and by the agitation dueto the meeting ofthese streams, the oil particles are thoroughlydispersed and mixed with air. v At the samev time the heat generatedforces flow of the gases at high velocity from the center throughout thewhole combustion space.

By this means, namely, agitation of the air and central initialcombustion, a rapid and thorough intermingling of fuel particles and airis accomplished and the fuel is completedly burned in the limited timeof the subsequent working stroke of the engine and without requiringanylarge excess of an.

Although the air in the auxiliary chamber is heated by compression abovethe fuel ignition temperature before injection commences, that is nodetriment because the quantity of air is not suflicient to burn anylarge proportion'of the fuel, while the heat ton displaces the spentgases which have entered during the working stroke, in the same way thatit displaces air and fuel oil upon the compression stroke, wherebycomplete scavenging of the spent gases takes place.

The invention embodiedin the means here described may be applied to anengine of any number of cylinders; and any working cylinder may have aplurality of auxiliary cylinders, or the same auxiliary cylindermayinject fuel into more than one cylinder in the case of an engine havingso large a numberof cylinders that more than one have their events incommon.

The foregoing explanation has been given as of the application to anengine operating on the four stroke cycle, but the essential principlesof means for injecting the fuel and agitating and mixing fuel and airare applicable to two cycle engines as well; and these same principlesmay be embodied in other mechanical forms and other proportions,dimensions, and arrangements than the specific ones here shown.Therefore I do not restrict the scone in which I claim protection to theprecise design shown; and of course no restriction is to be implied fromthe fact that the cylinder is shown upright rather than inverted,recumbent, or inclined, or from the words used in the specificationindicating relative height, such as above, below, and so forth.

ters Patent is: j

1. A fuel injection means for a high compression internal combustionengine,

comprising the combination with the cyl- What I claim and desire tosecure by Let- 2. A high compression internal combus-' tion enginecomprising in combination with the mam cylinder and piston, an auxiliarychamber closed at one end, a piston work-' ing therein, means fordelivering oil fuel into the auxiliar chamber between its closed end andthe ad acent end of the latter piston, and a communicating passageleading from the side of the auxiliary chamber to the combustion spaceof the main cylinder, the auxiliary piston being arranged to cross saidpassage and constructed to cause mechanical subdivisionof the fuel inits flow from said closed end part of the auxiliary chamber to saidpassage.

3. A high compression internal combustion engine comprising thecombination with a main cylinder and a piston, of an auxiliary cylinder,a transfer passage from the combustion chamber of said main cylinder tothe side of the auxiliary c linder, a fuel oil. inlet passage in the sie of the auxiliary cylinder extending in a line crossing theprolongation of the transfer passage Within the auxiliary cylinder, anauxiliary piston working in the latter cylinder adapted to cross theinner orifices of both said passages and having its external surfaceformed to permit flow past it of oil and air from the head end of theauxiliary cylinder through the transfer passage in numerous fine andobstructed streams.

4. A fuel injection means for an internal combustion engine comprising achamber adapted to receive air and oil, a piston fitting approximatelyleakage tight in said chamber, and a transfer passage leading from theside of the chamber, the piston having a zone provided with numerousshallow and narrow intersecting grooves form-- lng zigzag channels, thediameter of the chamber being enlarged near its end to provide anannular space giving access to said channels. I

5. A fuel injection means for an internal combustion engine comprising achamber adapted to receive air and oil, a piston fitting approximatelyleakage tight in said chamber, and a transfer passage leading from theside of the chamber at a point where its entrance orifice is traversedby the end part,

of said piston, the'piston having in its side a Zone provided witlnumerous shallow and narrow intersecting grooves forming zigzagchannels, the diameter of the chamber being enlarged near its end toprovide an annular space giving'access to said channels, and said pistonhaving also an encircling groove into which said channels lead and'alongitudinal groove adapted to register with the transfer passage. g

6. An internal combustion engine comprising a main cylinder and piston,an auxiliary cylinder and piston adapted to receive air and fuel oil, atransfer passage from the auxiliary cylinder into the main cylinderdirected toward the center of the combustion space in the latter, meansfor actuating the auxiliary piston to expel compressed air and fuel oilthrough said passage at the time of highest compression in the maincylinder, and guiding means in the main cylinder arranged to causestreams of air undergoing compression therein by the main piston to meetin the neighborhood of the center of said combustion space, whereby tocause agi tation of the air and fuel in such space at the time of fuelinjection.

7. An internal combustion engine of the high compression type comprisingin combination with a 'main cylinder and a piston, an auxiliarycylinder, a transfer passage adapted to conduct air between the maincylinder and the auxiliary cylinder, a fuel inlet to the auxiliarycylinder arranged to direct a stream of liquid fuel across the stream ofair flowing through said transfer passage into the auxiliary chamber,and a piston operable in said auxiliary cylinder to displace mingled airand fuel therefrom into the main cylinder. I

8. An internal combustion engine of the high compression type comprisingin comthrough said transfer passage into a body.

of highly compressed air in the main cylinder, the piston having meansfor mechanicallysubdividing the fuel.

In testimony whereof I have affixed my signature.

EUGENE A. FORD.

